Pay-per-use devices, such as those found in Laundromats may rely primarily on cash (e.g., coins and bills) as the payment method. Reliance on bills and coins may require additional servicing of bill and coin readers as well as scheduled collection of generated revenues. Fraud may occur through the use of slugs or other tokens in the coin slots. To counteract acceptance of fraudulent bills, bill readers may be highly sensitive such that worn bills may not be acceptable.